Anthony Watts, founder of the surfacestations.org project has an interesting video about the history of the surface stations used to measure changes in global temperature ie Global Warming/Cooling. Its turns out that the distribution of data has changed over time. Now, ideally, if you are measuring Global Warming, you’d want stations to cover as much of the Globe as possible. And of course you’d want to account for other things as well. But the available data for calculating these changes has itself changed. If you didn’t really need those numbers you might throw up your hands at this point. But Climate Scientists decided instead to attempt to correct for these problems. Did they correct for them properly? I dont know. I suspect not, and somepaperswouldseem to back me up on that. Bottom line: the data we use to say that it is warmer now than only a half century ago are questionable. The fact that the data have changed in this way should make those who are so sure of the science puase and reflect for a moment.